[PATCH 1/2] drm/panel: visionox-r66451: Send the brightness value MSB first

[Vladimir Zapolskiy <vz@kernel.org>]

The panel expects to get two bytes of the DCS Set Display Brightness
command with the most significant byte first, and it uses the lower
12 bits of the value, use mipi_dsi_dcs_set_display_brightness_large()
to correct the programmed brightness values.

Tested on the SM8350-HDK display card, the display brightness increases
gradually with:

  for v in $(seq 16 16 4095); do sleep 0.1; \
    echo $v > /sys/class/backlight/ae94000.dsi.0/brightness; \
  done

while without the change the display is dark during all writes.

Fixes: a6dfab2738fc ("drm/panel: Add driver for Visionox r66451 panel")
Signed-off-by: Vladimir Zapolskiy <vz@kernel.org>
---
 drivers/gpu/drm/panel/panel-visionox-r66451.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/panel/panel-visionox-r66451.c b/drivers/gpu/drm/panel/panel-visionox-r66451.c
index 1efb139bb711..4f28bd3b6080 100644
--- a/drivers/gpu/drm/panel/panel-visionox-r66451.c
+++ b/drivers/gpu/drm/panel/panel-visionox-r66451.c
@@ -227,7 +227,7 @@ static int visionox_r66451_bl_update_status(struct backlight_device *bl)
 	struct mipi_dsi_device *dsi = bl_get_data(bl);
 	u16 brightness = backlight_get_brightness(bl);
 
-	return mipi_dsi_dcs_set_display_brightness(dsi, brightness);
+	return mipi_dsi_dcs_set_display_brightness_large(dsi, brightness);
 }
 
 static const struct backlight_ops visionox_r66451_bl_ops = {
-- 
2.51.0